When Tony Blair's memoir, A Journey, was released last week, columnists and reviewers focused on his fairly unrevealing comments about the Iraq war. Less widely reported is Blair's account of his other major misjudgment in the Middle East: his stubborn refusal to call for a ceasefire during the 2006 Lebanon war.

The conflict, fought for a month between the Israel Defence Forces (IDF) and Hezbollah, was estimated to have cost the lives of 1,191 Lebanese citizens and 159 Israelis (including 43 civilians). As the Shia militia fired rockets at Israeli cities and the IDF responded with massive bombings in Lebanon, Blair was urged by a huge swell of public opinion, the media, his cabinet and foreign policy advisers to join European leaders in calling for an immediate unconditional ceasefire.

Yet the prime minister stubbornly defied this advice and endorsed the Bush administration's approach of foot-dragging on a UN ceasefire, allegedly to allow Israel more time to "knock out" Hezbollah.

Previous biographies, such as Anthony Seldon's excellent Blair Unbound, suggested Blair told aides that his attitude in summer 2006 was to retain "leverage" with both the US and Israel, fearing that to openly criticise them would lose him clout. Indeed, this was a reason often given for sticking with Bush in Iraq: to earn the right to guide and influence. Yet his memoir reveals no such pragmatic concerns, misguided as they proved to be. Instead, Blair declares a deep ideological motivation for opposing a ceasefire. He states: "If I had condemned Israel, it would have been more than dishonest; it would have undermined the world view I had come to hold passionately."

It is this world view that is most alarming about Blair's account. Through this lens, Blair believed: "Lebanon was embroiled in something far bigger and more portentous than a temporary fight with Israel." Instead, he sees it as a "wider struggle between the strain of religious extremism in Islam and the rest of us". He was thus willing to delay a ceasefire in order to win victory in this wider struggle, of which he saw Hezbollah as a key combatant, and Israel as one of "us".

From Blair's perspective this religious struggle defines the Middle East. He states: "To me, you can't understand Hezbollah unless you understand the role of Iran; or understand Lebanon unless you understand Syria … or understand either country in its present state unless you understand the history not just of the region but of the religion, how it saw itself, how it had developed its own narrative, how it saw its own predicament."

This includes a remarkable simplification of the Israel-Palestine conflict, which he claims "is used as a potent source of friction and war because of religious difference". The impact of other significant forces, notably nationalism and imperialism, are conveniently sidelined.

Blair hints that the civilians caught up in this struggle are regrettably expendable. Echoing Condoleezza Rice's own distasteful remarks that the 2006 violence was the "birth pangs of a new Middle East", Blair remarks that "just because we were shocked by the TV footage of the consequences of war, this could not blind us to the consequences of peace on the wrong terms".

Yet his peace on the "right" terms seemed to include a form of collective punishment of the Lebanese. He articulates: "They [Hezbollah] had to understand that if they tried doing it again, there was a price to be paid that the people of Lebanon would not allow them to pay, at least not with the lives of their civilians."

One wonders if Blair would have been willing to expend the lives of a thousand Israeli, or even British, civilians in order to make Hezbollah understand.

The use of force to achieve his goals is a further strand of his world view. He states: "The solution to me lay in neither the sole use of hard power nor the sole use of soft power but in the combination of the two." Moreover, he was willing to overrule all advice and his public to achieve this. He remarks: "It wasn't that I didn't get public opinion on Lebanon, nor that I couldn't have articulated it. My difficulty was that I didn't agree with it."

Yet there was a high cost to this ideological stubbornness. Blair's book dwells on the domestic consequence of his actions, claiming they led to his departure from office, but the costs to Lebanon and the Middle East in general were far greater. When Hezbollah was still standing after the war it claimed a "divine victory" boosting its power and influence. At the same time, the Lebanese government that had come to power trying to reorientate Beirut into a more western orbit was hugely undermined, as its supposed new allies seemed powerless to defend its infrastructure and civilians from Israeli attacks. This caused more internal strife before a Syrian-Saudi-backed stability emerged in 2008.

The reverse of what Blair intended had occurred: Hezbollah and its allies were boosted, Israel was demoralised, the US and Britain were further discredited in Arab eyes, and an excessive number of civilians had died in the pursuit of an unobtainable ideological goal.

A Journey thus presents Blair's actions in summer 2006 as those of a committed ideologue, not simply Bush's poodle as previously charged. Blair seems driven by a world view that, though not explicitly neoconservative, certainly has similarities. He sees the Middle East through a largely religious lens, frames its complex conflicts though a simplified struggle between radical and moderate Islam and is willing to use force and sacrifice lives to achieve its aims, irrespective of public and expert opinion.

However, what is most alarming about this is not necessarily the ideology behind the misjudgment in Lebanon four years ago. It is that Blair retains this misguided zeal today and somehow expects to use it to deliver the "right peace" between Israelis and Palestinians in his role as quartet envoy.